Selection Bias Requires Selection: The Case of Collider Stratification Bias.

In epidemiology, collider stratification bias, the bias resulting from conditioning on a common effect of two causes, is oftentimes considered a type of selection bias, regardless of the conditioning methods employed. In this commentary, we distinguish between two types of collider stratification bias: collider restriction bias due to restricting to one level of a collider (or a descendant of a collider) and collider adjustment bias through inclusion of a collider (or a descendant of a collider) in a regression model. We argue that categorizing collider adjustment bias as a form of selection bias may lead to semantic confusion, as adjustment for a collider in a regression model does not involve selecting a sample for analysis. Instead, we propose that collider adjustment bias can be better viewed as a type of overadjustment bias. We further provide two distinct causal diagram structures to distinguish collider restriction bias and collider adjustment bias. We hope that such a terminological distinction can facilitate easier and clearer communication.

The Evolution of Selection Bias in the Recent Epidemiologic Literature-A Selective Overview.

Selection bias has long been central in methodological discussions across epidemiology and other fields. In epidemiology, the concept of selection bias has been continually evolving over time. In this issue of the Journal, Mathur and Shpitser (Am J Epidemiol. XXXX;XXX(XX):XXXX-XXXX) present simple graphical rules for using a Single World Intervention Graph (SWIG) to assess the presence of selection bias when estimating treatment effects in both the general population and a selected sample. Notably, the authors examine the setting in which the treatment affects selection, an issue not well-addressed in the existing literature on selection bias. To place the work by Mathur and Shpitser in context, we review the evolution of the concept of selection bias in epidemiology, with a primary focus on the developments in the last 20-30 years since the introduction of causal directed acyclic graphs (DAGs) to epidemiologic research.

Substance use in a Dutch migraine cohort compared with the general population.

OBJECTIVE: To evaluate self-reported substance user profiles for individuals with migraine and compare these to the general population. BACKGROUND: There is increasing attention to lifestyle influences such as substance use as presumed migraine triggers. METHODS: Data on substance use were collected by survey in a large migraine cohort and from the biannual survey in the general Dutch population for substances. A representative cohort of Dutch patients with migraine (n = 5176) and the Dutch general population (n = 8370) was included. Patients with migraine were subdivided into episodic (EM) and chronic migraine (CM). Substance consumption was compared between the general population and patients with migraine, and between migraine subgroups after standardization for sex and level of education. RESULTS: Included patients with migraine were 83.4% female (4319/5176) and had a mean (standard deviation) age of 44.8 (11.3) years. Patients with migraine reported less illicit drug use (odds ratio [OR] 0.48, 95% confidence interval [CI] 0.42-0.55; p < 0.001), less current and lifetime smoking (OR 0.60, 95% CI 0.55-0.65; p < 0.001 and OR 0.75, 95% CI 0.71-0.79; p < 0.001), and less current alcohol consumption (OR 0.66, 95% CI 0.62-0.70; p < 0.001) compared with the general population. Prevalence of substance use was compared between CM and EM participants and showed higher illicit drug use (OR 1.73, 95% CI 1.11-2.69; p = 0.011), higher current smoking (OR 1.61, 95% CI 1.22-2.11; p < 0.001) but less alcohol use (OR 0.54, 95% CI 0.43-0.68; p < 0.001) for participants with CM compared with EM. No differences were found for a history of smoking (OR 1.18, 95% CI 0.92-1.50, p = 0.19). CONCLUSIONS: Individuals with migraine are less likely to use illicit drugs, smoke, or drink alcohol compared with the general population. Patients with CM less often consume alcohol, while they more often use illicit drugs and smoke compared to those with EM.

Sequential Data-Mining for Adverse Events After Recombinant Herpes Zoster Vaccination Using the Tree-Based Scan Statistic.

Tree-based scan statistics have been successfully used to study the safety of several vaccines without prespecifying health outcomes of concern. In this study, the binomial tree-based scan statistic was applied sequentially to detect adverse events in days 1-28 compared with days 29-56 after recombinant herpes zoster (RZV) vaccination, with 5 looks at the data and formal adjustment for the repeated analyses over time. IBM MarketScan data on commercially insured persons ≥50 years of age receiving RZV during January 1, 2018, to May 5, 2020, were used. With 999,876 doses of RZV included, statistically significant signals were detected only for unspecified adverse effects/complications following immunization, with attributable risks as low as 2 excess cases per 100,000 vaccinations. Ninety percent of cases in the signals occurred in the week after vaccination and, based on previous studies, likely represent nonserious events like fever, fatigue, and headache. Strengths of our study include its untargeted nature, self-controlled design, and formal adjustment for repeated testing. Although the method requires prespecification of the risk window of interest and may miss some true signals detectable using the tree-temporal variant of the method, it allows for early detection of potential safety problems through early initiation of ongoing monitoring.

The importance of using disease causal models in studies of preventive interventions: Learning from preeclampsia research.

OBJECTIVE: Interventions aimed at preventing disease are commonly studied as strategies of primary or secondary prevention. Unfortunately, this dichotomy can be misleading, and studies might unknowingly exclude people at high risk of the disease that could benefit from the intervention. Here I use the example of aspirin for prevention of preeclampsia to illustrate this problem. METHODS: I use directed acyclic graphs to represent several causal models of aspirin and preeclampsia, each making different assumptions regarding the causal relation between previous preeclampsia, aspirin, and subsequent preeclampsia. Afterwards, I discuss the implications of each model. RESULTS: Aspirin started being recommended to pregnant women that had presented preeclampsia in previous pregnancies, but not to women at high risk due to other factors. Studies started evaluating aspirin in women at high risk due to these other causes and found it also reduced the risk of preeclampsia in them. Thanks to a shift towards risk-based interventions, guidelines started recommending aspirin to all women considered at high risk of preeclampsia. Furthermore, recent studies have begun using blood markers in women without classic risk factors to identify additional women that might benefit from aspirin. With such advances, performing "secondary prevention" once the first event occurred will increasingly represent a failure to intervene on time. CONCLUSIONS: Explicitly illustrating disease causal models helps to identify those individuals that are most likely to benefit from risk reduction, regardless of whether they were previously afflicted by the disease. This is beneficial when designing studies and when implementing preventive interventions.

Future Research by the Australian Chiropractic Profession: Analysis of Comments and Suggestions From a Nationwide Survey of Academics and Practitioners.

OBJECTIVE: The purpose of this study was to identify and compare the research priorities of Australian practicing chiropractors and academics across listed research domains and to seek their views on existing chiropractic research strategies. Concurrent objectives were to gain insight into the perspectives on characteristics of research and solicit ideas and suggestions for future research from both groups. METHODS: This study used a mixed-method research design to collect data using an online survey portal. Australian chiropractic academics (n = 220) and practicing chiropractors who were also members of a nationally representative, practice-based research network database (n = 1680) were invited to participate. Data were collected (February 19, 2019, to May 24, 2019). The free-text data were analyzed primarily via semantic coding and verbatim referential units in cases where the category was an exact match for the textual data. Content analyses of the qualitative data were presented in a tabulated and narrative manner as identified domains. Selected representative examples were provided verbatim. RESULTS: The response rate for the survey was 44% for full-time equivalent academics, 8% for casuals and part-time chiropractic academics, and 21.5% for Australian Chiropractic Research Network database chiropractic practitioners. Open-text data comprised a narrower focus on musculoskeletal (MSK) conditions and opposition or reservations by academics and some practitioners toward the research agenda of those espousing traditional concepts and terminology. Comments from both groups illustrate the strongly held views that characterize divergent factions of the chiropractic profession. Some practitioners were highly critical of the narrow focus and epistemological paradigm of Australian university-based research, while others were strongly supportive of the traditional focus of the Australian Spinal Research Foundation. Australian academics at the 4 university-based programs held the view that MSK and spinal pain, for which some evidence already exists, should be the priority of future research, building on what is known. Practitioners believed that future research should be directed toward expanded areas such as basic science, younger populations, and non-MSK conditions. Respondents were sharply divided on attitudes toward traditional chiropractic terminology, concepts, and philosophy and the utility of future research on these topics. CONCLUSION: Our qualitative findings suggest there is a division in the Australian chiropractic profession regarding research direction and priorities. This divide exists between academics and researchers and within field practitioners. This study highlights the attitudes, opinions, and perceptions of important stakeholder groups, which should be considered by decision-makers when formulating research policy, strategy, and prioritization of funding.

A Clinical Prediction Model for Unsuccessful Pulmonary Tuberculosis Treatment Outcomes.

BACKGROUND: Despite widespread availability of curative therapy, tuberculosis (TB) treatment outcomes remain suboptimal. Clinical prediction models can inform treatment strategies to improve outcomes. Using baseline clinical data, we developed a prediction model for unsuccessful TB treatment outcome and evaluated the incremental value of human immunodeficiency virus (HIV)-related severity and isoniazid acetylator status. METHODS: Data originated from the Regional Prospective Observational Research for Tuberculosis Brazil cohort, which enrolled newly diagnosed TB patients in Brazil from 2015 through 2019. This analysis included participants with culture-confirmed, drug-susceptible pulmonary TB who started first-line anti-TB therapy and had ≥12 months of follow-up. The end point was unsuccessful TB treatment: composite of death, treatment failure, regimen switch, incomplete treatment, or not evaluated. Missing predictors were imputed. Predictors were chosen via bootstrapped backward selection. Discrimination and calibration were evaluated with c-statistics and calibration plots, respectively. Bootstrap internal validation estimated overfitting, and a shrinkage factor was applied to improve out-of-sample prediction. Incremental value was evaluated with likelihood ratio-based measures. RESULTS: Of 944 participants, 191 (20%) had unsuccessful treatment outcomes. The final model included 7 baseline predictors: hemoglobin, HIV infection, drug use, diabetes, age, education, and tobacco use. The model demonstrated good discrimination (c-statistic = 0.77; 95% confidence interval, .73-.80) and was well calibrated (optimism-corrected intercept and slope, -0.12 and 0.89, respectively). HIV-related factors and isoniazid acetylation status did not improve prediction of the final model. CONCLUSIONS: Using information readily available at treatment initiation, the prediction model performed well in this population. The findings may guide future work to allocate resources or inform targeted interventions for high-risk patients.

A Broad Safety Assessment of the Recombinant Herpes Zoster Vaccine.

The recombinant herpes zoster vaccine (RZV), approved as a 2-dose series in the United States in October 2017, has proven highly effective and generally safe. However, a small risk of Guillain-Barré syndrome after vaccination was identified after approval, and questions remain about other possible adverse events. This data-mining study assessed RZV safety in the United States using the self-controlled tree-temporal scan statistic, scanning data on thousands of diagnoses recorded during follow-up to detect any statistically unusual temporal clustering of cases within a large hierarchy of diagnoses. IBM MarketScan data on commercially insured persons at least 50 years of age receiving RZV between January 1, 2018, and May 5, 2020, were used, including 56 days of follow-up; 1,014,329 doses were included. Statistically significant clustering was found within a few days of vaccination for unspecified adverse effects, complications, or reactions to immunization or other medical substances/care; fever; unspecified allergy; syncope/collapse; cellulitis; myalgia; and dizziness/giddiness. These findings are consistent with the known safety profile of this and other injected vaccines. No cluster of Guillain-Barré syndrome was detected, possibly due to insufficient sample size. This signal-detection method has now been applied to 5 vaccines, with consistently plausible results, and seems a promising addition to vaccine-safety evaluation methods.

Dental caries and depression in pregnant women: The role of oral health self-perception as mediator.

OBJECTIVE: This study investigated the role of oral health self-perception as mediator of association between dental caries and depression among pregnant women from the 2015 Pelotas Birth Cohort Study, Brazil. MATERIALS AND METHODS: Overall, 2,496 pregnant women participated of this oral health sub-study. Data related to demographic and socioeconomic conditions, lifetime and current depression, and oral health self-perception were collected. Participants were also assessed for dental caries (DMF-T index). Depression was assessed using the Edinburgh Postnatal Depression Scale. For analysis, six outcomes related to dental caries experience were considered. Causal mediation analysis was performed using parametric regression models. RESULTS: When it was assumed that all subjects had poor perception about oral health, it was observed that the presence of moderate/severe depressive signals and symptoms was higher in subjects with dental caries experience (OR 1.13; CI 95% 1.06-1.20), with severity of untreated dental caries (OR 2.08; CI 95% 1.16-3.78), untreated dental caries (OR 1.18; 95% CI 1.07-1.29), tooth loss (OR 1.08; 95% CI 1.02-1.14), and filled tooth (OR 1.07; 95% CI 1.02-1.16). CONCLUSIONS: Our findings show the effect of dental caries on depression is mediated by self-perception about oral health in pregnant women.

Seasonality of SARS-CoV-2 Infections in G20 Countries: Ecological Analysis of Publicly Available Data.

Previous laboratory studies of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) revealed that the stability of the virus in the air or on surfaces is sensitive to seasonally relevant environmental conditions. However, the seasonality of the virus in the real world remains unclear because each country adopted various infection control policies. Therefore, we investigated peak dates with regard to new confirmed cases of coronavirus disease 2019 (COVID-19) and an association of these dates with the timing of the lockdown among G20 countries that have four seasons from 1 June 2020 to 18 February 2021. As a result, countries in both hemispheres experienced seasonal peaks in the number of COVID-19 cases both in the middle of warm and cold seasons. In addition, there were no apparent relationships between the peak date and periods with stringent measures. Our study demonstrated that SARS-CoV-2 causes seasonal outbreaks in the winter and possibly summer and thus, countries might need to consider measures to prepare for resurgence of the virus in the middle of 2021.

Invited Commentary: The Society for Epidemiologic Research Annual Meeting-Room to Improve Gender Equity.

The annual meeting of the Society for Epidemiologic Research is a prominent showcase for epidemiologists to present their research and share their expertise with peers. There are multiple paths to being on a podium at the meeting, and that role has implications for not only the speaker but also the audience. The article by Nobles et al. (Am J Epidemiol. 2021;190(9):1710-1720) represents an innovative investigation of representation among speakers at 3 recent SER annual meetings, with a primary focus on gender. Women were significantly under-represented as symposium speakers, which is an important role at the meeting. Symposium talks are invited talks and thus recognition of stature in the field. However, women were not under-represented as speakers in the concurrent contributed sessions, which are not invited talks and undergo blinded peer review. This gender contrast between the speakers at concurrent contributed sessions and the symposia is likely due to the different submission processes for the 2 types of presentations, but it could also reflect the review processes. Although the symposia are highly informative and enjoyable components of the meetings, some modifications in the submission and evaluation processes may be beneficial.

The effect of the Affordable Care Act dependent coverage provision on HPV vaccine uptake in young adult women, National Health and Nutrition Examination Survey 2007-2016.

The human papillomavirus (HPV) vaccine protects against cancers caused by HPV. The study objective was to examine the effect of the Affordable Care Act (ACA) dependent child coverage provision on HPV vaccination initiation, HPV vaccine completion, HPV infection, and health insurance coverage among young women. Using cross-sectional data from the National Health and Nutrition Examination Survey (NHANES), 2172 female participants were included. The impact of the dependent coverage provision on the four outcomes was examined using difference-in-difference analyses with linear probability regressions, controlling for race/ethnicity, age, income, head of household education, and family employment. ACA exposure group was operationalized by age, with those targeted by the dependent coverage provision (ages 19-25) serving as the intervention group and those similar in age but not targeted (ages 18 and 26) serving as the control group. From 2007 to 2016, HPV vaccine initiation, HPV vaccine completion, and health insurance prevalence increased and HPV infection prevalence decreased. In the difference-in-difference adjusted models, ACA exposure was not associated with HPV vaccine initiation (0.045 percentage points [95% CI -0.087, 0.178]), completion (-0.044 percentage points [95% CI -0.152, 0.063]), HPV 16/18 infection (-0.051 percentage points [95% CI -0.123, 0.021]), or health insurance (0.065 percentage points [95% CI -0.032, 0.162]) among women aged 19 to 25. The dependent coverage provision may not have addressed relevant barriers to HPV vaccination. However, given that the effect of the dependent coverage provision on HPV vaccination and health insurance has been demonstrated previously, small sample size is a concern.

Assessing knowledge, attitudes, and practices towards causal directed acyclic graphs: a qualitative research project.

Causal graphs provide a key tool for optimizing the validity of causal effect estimates. Although a large literature exists on the mathematical theory underlying the use of causal graphs, less literature exists to aid applied researchers in understanding how best to develop and use causal graphs in their research projects. We sought to understand why researchers do or do not regularly use DAGs by surveying practicing epidemiologists and medical researchers on their knowledge, level of interest, attitudes, and practices towards the use of causal graphs in applied epidemiology and health research. We used Twitter and the Society for Epidemiologic Research to disseminate the survey. Overall, a majority of participants reported being comfortable with using causal graphs and reported using them 'sometimes', 'often', or 'always' in their research. Having received training appeared to improve comprehension of the assumptions displayed in causal graphs. Many of the respondents who did not use causal graphs reported lack of knowledge as a barrier to using DAGs in their research. Causal graphs are of interest to epidemiologists and medical researchers, but there are several barriers to their uptake. Additional training and clearer guidance are needed. In addition, methodological developments regarding visualization of effect measure modification and interaction on causal graphs is needed.

The accuracy of administrative health data for identifying patients with rheumatoid arthritis: a retrospective validation study using medical records in Western Australia.

The use of administrative health datasets is increasingly important for research on disease trends and outcome. The Western Australian (WA) Rheumatic Disease Epidemiological Registry contains longitudinal health data for over 10,000 patients with rheumatoid arthritis (RA). Accurate coding for RA is essential to the validity of this dataset. Investigate the diagnostic accuracy of International Classification of Diseases (ICD)-based discharge codes for RA at WA's largest tertiary hospital. Medical records for a sample of randomly selected patients with ICD-10 codes (M05.00-M06.99) in the hospital discharge database between 2008 and 2020 were retrospectively reviewed. Rheumatologist-reported diagnoses and ACR/EULAR classification criteria were used as reference standards to determine accuracy measures. Medical chart review was completed for 87 patients (mean (± SD) age 64.7 ± 17.2 years), 67.8% female). A total of 80 (91.9%) patients had specialist confirmed RA diagnosis, while seven patients (8%) had alternate clinical diagnoses. Among 87 patients, 69 patients (79.3%) were fulfilled ACR/EULAR classification criteria. The agreement between the reference standards was moderate (Kappa 0.41). Based on rheumatologist-reported diagnoses and ACR/EULAR classification criteria, primary diagnostic codes for RA alone had a sensitivity of (90% vs 89.8%), and PPV (90.9% vs 63.6%), respectively. A combination of a diagnostic RA code with biologic infusion codes in two or more codes increased the PPV to 97.9%. Hospital discharge diagnostic codes in WA identify RA patients with a high degree of accuracy. Combining a primary diagnostic code for RA with biological infusion codes can further increase the PPV.

Hospital Records of Pain, Fatigue, or Circulatory Symptoms in Girls Exposed to Human Papillomavirus Vaccination: Cohort, Self-Controlled Case Series, and Population Time Trend Studies.

Human papillomavirus (HPV) vaccination has been associated with subsequent diffuse symptoms in girls, reducing public confidence in the vaccine. We examined whether girls have nonspecific outcomes of HPV vaccination, using triangulation from cohort, self-controlled case series (SCCS), and population time trend analyses carried out in Denmark between 2000 and 2014. The study population consisted of 314,017 HPV-vaccinated girls and 314,017 age-matched HPV-unvaccinated girls (cohort analyses); 11,817 girls with hospital records (SCCS analyses); and 1,465,049 girls and boys (population time trend analyses). The main outcome measures were hospital records of pain, fatigue, or circulatory symptoms. The cohort study revealed no increased risk among HPV vaccine-exposed girls, with incidence rate ratios close to 1.0 for abdominal pain, nonspecific pain, headache, hypotension/syncope, tachycardia (including postural orthostatic tachycardia syndrome), and malaise/fatigue (including chronic fatigue syndrome). In the SCCS analyses, we observed no association between HPV vaccination and subsequent symptoms. In time trend analyses, we observed a steady increase in these hospital records in both girls and (HPV-unvaccinated) boys, with no relationship to the 2009 introduction of HPV vaccine to Denmark's vaccination program. This study, which had nationwide coverage, showed no evidence of a causal link between HPV vaccination and diffuse autonomic symptoms leading to hospital contact.

Improving Diversity and Promoting Inclusion in the Society for Epidemiologic Research Through Choice of Conference Location.

Scientific conferences provide attendees opportunities to network, share research, learn new skills and ideas, and initiate collaborations. Conference attendance is especially important for students and early-career researchers who are establishing their research careers or looking for jobs. However, attending conferences can be expensive, and the high cost of conference attendance might hit students and early-career researchers the hardest. According to a new member survey from the Society for Epidemiologic Research, early-career members are more racially and ethnically diverse than senior members, meaning that reducing financial barriers to conference participation might be an important consideration for increasing diversity among conference attendees. In this commentary, we discuss how choice of conference location-choosing less expensive cities nearer to more Society for Epidemiologic Research members-could reduce financial and other barriers to conference attendance for all members and improve diversity and inclusion in the Society.

Improving design choices in Delphi studies in medicine: the case of an exemplary physician multi-round panel study with 100% response.

BACKGROUND: A proper application of the Delphi technique is essential for obtaining valid research results. Medical researchers regularly use Delphi studies, but reports often lack detailed information on methodology and controlled feedback: in the medical literature, papers focusing on Delphi methodology issues are rare. Since the introduction of electronic surveys, details on response times remain scarce. We aim to bridge a number of gaps by providing a real world example covering methodological choices and response times in detail. METHODS: The objective of our e(lectronic)-Delphi study was to determine minimum standards for emergency departments (EDs) in the Netherlands. We opted for a two-part design with explicit decision rules. Part 1 focused on gathering and defining items; Part 2 addressed the main research question using an online survey tool. A two-person consensus rule was applied throughout: even after consensus on specific items was reached, panellists could reopen the discussion as long as at least two panellists argued similarly. Per round, the number of reminders sent and individual response times were noted. We also recorded the methodological considerations and evaluations made by the research team prior to as well as during the study. RESULTS: The study was performed in eight rounds and an additional confirmation round. Response rates were 100% in all rounds, resulting in 100% consensus in Part 1 and 96% consensus in Part 2. Our decision rules proved to be stable and easily applicable. Items with negative advice required more rounds before consensus was reached. Response delays were mostly due to late starts, but once panellists started, they nearly always finished the questionnaire on the same day. Reminders often yielded rapid responses. Intra-individual differences in response time were large, but quick responders remained quick. CONCLUSIONS: We advise those considering Delphi study to follow the CREDES guideline, consider a two-part design, invest in personal commitment of the panellists, set clear decision rules, use a consistent lay-out and send out your reminders early. Adopting this overall approach may assist researchers in future Delphi studies and may help to improve the quality of Delphi designs in terms of improved rigor and higher response rates.

Predictors of Response Outcomes for Research Recruitment Through a Central Cancer Registry: Evidence From 17 Recruitment Efforts for Population-Based Studies.

When recruiting research participants through central cancer registries, high response fractions help ensure population-based representation. We conducted multivariable mixed-effects logistic regression to identify case and study characteristics associated with making contact with and obtaining cooperation of Utah cancer cases using data from 17 unique recruitment efforts undertaken by the Utah Cancer Registry (2007-2016) on behalf of the following studies: A Population-Based Childhood Cancer Survivors Cohort Study in Utah, Comparative Effectiveness Analysis of Surgery and Radiation for Prostate Cancer (CEASAR Study), Costs and Benefits of Follow-up Care for Adolescent and Young Adult Cancers, Study of Exome Sequencing for Head and Neck Cancer Susceptibility Genes, Genetic Epidemiology of Chronic Lymphocytic Leukemia, Impact of Remote Familial Colorectal Cancer Risk Assessment and Counseling (Family CARE Project), Massively Parallel Sequencing for Familial Colon Cancer Genes, Medullary Thyroid Carcinoma (MTC) Surveillance Study, Osteosarcoma Surveillance Study, Prostate Cancer Outcomes Study, Risk Education and Assessment for Cancer Heredity Project (REACH Project), Study of Shared Genomic Segment Analysis and Tumor Subtyping in High-Risk Breast-Cancer Gene Pedigrees, Study of Shared Genomic Segment Analysis for Localizing Multiple Myeloma Genes. Characteristics associated with lower odds of contact included Hispanic ethnicity (odds ratio (OR) = 0.34, 95% confidence interval (CI): 0.27, 0.41), nonwhite race (OR = 0.46, 95% CI: 0.35, 0.60), and younger age at contact. Years since diagnosis was inversely associated with making contact. Nonwhite race and age ≥60 years had lower odds of cooperation. Study features with lower odds of cooperation included longitudinal design (OR = 0.50, 95% CI: 0.41, 0.61) and study brochures (OR = 0.70, 95% CI: 0.54, 0.90). Increased odds of cooperation were associated with including a questionnaire (OR = 3.19, 95% CI: 1.54, 6.59), postage stamps (OR = 1.60, 95% CI: 1.21, 2.12), and incentives (OR = 1.62, 95% CI: 1.02, 2.57). Among cases not responding after the first contact, odds of eventual response were lower when >10 days elapsed before subsequent contact (OR = 0.71, 95% CI: 0.59, 0.85). Obtaining high response is challenging, but study features identified in this analysis support better results when recruiting through central cancer registries.

Using the Self-Controlled Tree-Temporal Scan Statistic to Assess the Safety of Live Attenuated Herpes Zoster Vaccine.

The self-controlled tree-temporal scan statistic allows detection of potential vaccine- or drug-associated adverse events without prespecifying the specific events or postexposure risk intervals of concern. It thus opens a promising new avenue for safety studies. The method has been successfully used to evaluate the safety of 2 vaccines for adolescents and young adults, but its suitability to study vaccines for older adults had not been established. The present study applied the method to assess the safety of live attenuated herpes zoster vaccination during 2011-2017 in US adults aged ≥60 years, using claims data from Truven Health MarketScan Research Databases. Counts of International Classification of Diseases diagnosis codes recorded in emergency department or hospital settings were scanned for any statistically unusual clustering within a hierarchical tree structure of diagnoses and within 42 days after vaccination. Among 1.24 million vaccinations, 4 clusters were found: cellulitis on days 1-3, nonspecific erythematous condition on days 2-4, "other complications . . ." on days 1-3, and nonspecific allergy on days 1-6. These results are consistent with local injection-site reactions and other known, generally mild, vaccine-associated adverse events and a favorable safety profile. This method might be useful for assessing the safety of other vaccines for older adults.

Associations of insulin-like growth factor-I and insulin-like growth factor binding protein-3 with bone quality in the general adult population.

OBJECTIVE: Growth hormone (GH) and its main mediator, insulin-like growth factor-I (IGF-I), play a significant role in bone metabolism. The relations between IGF-I and bone mineral density (BMD) or osteoporosis have been assessed in previous studies but whether the associations are sex-specific remains uncertain. Moreover, only a few studies examined bone quality assessed by quantitative ultrasound (QUS). We aimed to investigate these associations in the general population of north-east Germany. DESIGN AND MEASUREMENTS: Data from 1759 men and 1784 women who participated in the baseline examination of the Study of Health in Pomerania (SHIP)-Trend were used. IGF-I and IGF-binding protein-3 (IGFBP-3) concentrations were measured on the IDS-iSYS multidiscipline automated analyser (Immunodiagnostic Systems Limited). QUS measurements were performed at the heel (Achilles InSight, GE Healthcare). Sex-specific linear and multinomial logistic regression models adjusted for potential confounders were calculated. RESULTS: Linear regression analyses revealed significant positive associations between IGF-I and IGF-I/IGFBP-3 ratio, a marker for free IGF-I, with all QUS parameters in men. Among women, we found an inverse association between IGF-I and the QUS-based fracture risk but no association with any other QUS parameter. There was no association between IGFBP-3 and the QUS-based fracture risk. CONCLUSIONS: Our data suggest an important role of IGF-I on bone quality in men. The observed association of IGF-I with the QUS-based stiffness index and QUS-based fracture risk in this study might animate clinicians to refer patients with low IGF-I levels, particularly men, to a further evaluation of risk factors for osteoporosis and a detailed examination of the skeletal system.